In general, users want to utilize an identical document multifariously, and even the same user does according to time and circumstances.
First, let's consider a case of reading a document.
FIGS. 15a and 15b show different fashions of use for the identical original document.
FIG. 15a illustrates the fashion wherein part 401 of the original document is underlined and is endowed with a comment 404, and wherein in reading the original document, the underline and the comment 404 are conjointly displayed. This fashion is suited to a case where the same user reads the original document at the second time et seq. while picking up only chief points, and a case where a certain user wants to refer to comments made by another user.
On the other hand, FIG. 15b illustrates the fashion wherein the meanings 405 of words 402 and 403 in the original document are afforded besides the given items in FIG. 15a, and wherein in reading the original document, the underline, comment 404 and word meanings 405 are conjointly displayed. In a case where the original document contains a large number of unknown words, the fashion of FIG. 15a is unsatisfactory, and the fashion of FIG. 15b is suitable.
In this manner, even the identical original document needs to be arranged into various fashions for utilization, depending upon users or according to time and circumstances.
Meanwhile, a technique intended to meet the requirement for the variable documental arrangement on a work station is "Hypertext" which is discussed in IEEE, Hypertext: An introduction and survey, Computer 2, 9 (1987), pp. 17-41. This technique is such that accessory information items on a document, for example, comments and the meanings of words, are managed separately from the original document, and that mapping from the original document to the set of the accessory information items is defined beforehand. On that occasion, the individual accessory information items are respectively held in correspondence with marks in the original document. Among the marks in the original document, only ones designated by the user have the corresponding accessory information items presented. According to this technique, the user can register the various items of accessory information in the document and can obtain only the required items in a desired sequence from among the registered accessory information.
Regarding the example of FIG. 15b, the original document is initially displayed in a fashion with quite no accompanying accessory information. Thereafter, when the user indicates to the effect that he/she wants to know the meaning of the word 402, the meaning of "experiential" is displayed near the word 402. In addition, when he/she indicates to the effect that the display is unnecessary, the original state is resumed.
In this manner, in the hypertext, the document has the multilevel construction unlike the construction in which all the accessory information items are contained flush in the original document as in a write operation. Further, in a case where the accessory information has a hierarchic structure, the user can obtain the accessory information items down to a desired depth.
Next, let's consider a case of generating a document. A user often wants to derive the other similar document from an original document in such a way that only parts are extracted from the original document or that letters and symbols are input anew.
FIG. 16a illustrates a thesis "Document B" which is the original document, while FIG. 16b illustrates a material for publication, "Document C" which has been derived from the original document.
The Document C is obtained in such a way that phrases 421b, 422b, 423b and 424b are first quoted from the Document B and turned into respective phrases 421c, 422c, 423c and 424c, that the layout of these phrases is subsequently revised properly, and that the number of a figure, etc. are further input anew. The user is sometimes conscious of the document thus derived from the original document, as the independent material for publication, "Document C" and sometimes as "matters generated from Document B" dependently.
Now, the case of reading the document will be considered again. With the hypertext, the accessory information items on the original document are merely handled in such a way that the user designates them one by one.
In general, in a case where a user utilizes a document, there is an arrangement fashion for the whole document, including that "the user wants to read with reference to the meanings of words" and that "he/she will not refer to comments". Besides, local alterations including that "as to the words having become known, he/she wants to erase the displays of the meanings" take place in the arrangement fashion. In order to meet the user's requirement for the variable documental arrangement, accordingly, the following two features are necessitated:
(1) Permitting the user to handle the original document in various arrangement fashions PA1 (2) Permitting the user to locally handle the accessory information in the original document in a predetermined arrangement fashion.
In the hypertext, the above requisite (2) is taken into account, but the requisite (1) is not.
More specifically, as to the example of FIG. 15b, even when unknown words are large in number, the user must designate the words 402, 403, . . . in succession so as to display the meanings thereof. He/she cannot systematically designate the "display of the meanings of words" so as to display the meanings 405 of all the registered words as illustrated in the figure, or designate the "display of comments" so as to display the comment 404 registered in the original document. Accordingly, even when the arrangement fashion that "the user wants to read with reference to the meanings of words" is determined by way of example, he/she needs to designate the words successively one by one for the displays of the meanings thereof.
Next, the case of generating the document will be considered as to the example of FIGS. 16a and FIG. 16b. In general, a document derived from an original document is managed as an independent one similarly to other documents which are quite different. Therefore, when the user wants to refer to the derived document, he/she must search for the document with its name "Document C" or the like as a key. If the user wants to search for the Document C on the basis of the relation of derivation such as "generated from the Document B", he/she must separately manage the relation of derivation between the documents, that "Document C has been derived from Document B". Moreover, unlike a mere copy, quotations from the original document into the derived document have the property that, when terms, data values, etc. have been updated in the original document, the updates need to be influenced on the derived document. In this regard, the prior art has the problem that the user must separately manage the relations of the update influencing.
Assuming that the various fashions of an identical document are managed as separate documents, the enlarged number of documents is difficult for the user to search for the document corresponding to a desired arrangement fashion and make it impossible to dynamically combine a plurality of such arrangement fashions that "both comments and the meanings of words will be referred to". Further, when the original document is updated, the same updates must be executed for all of the separate documents, resulting in a difficult transaction.
Accordingly, the hypertext has the problem that restrictions are imposed on utilizing the original document in various arrangement fashions.
Besides, the hypertext has the problem that the updates of the original document are not adequately influenced on the accessory information and the derived document.
The influencing of the updates of the original document will be described in connection with the example of FIG. 15a. It is supposed that the comment 404 is initially made for the passage 401 in the original document, whereupon the matter of the passage 401 is revised. Even the gist of the passage 401 is sometimes changed by the revision, and also the comment 404 must be deleted or altered on that occasion. In addition, the major part of the passage 401 commented on is sometimes moved to another place, and also the comments 404 must be moved to the destination of the original document on that occasion. In this manner, the updates of the original document often come to require those of the accessory information items associated therewith. With the hypertext, however, merely marks indicating to the effect of the registrations of comments are given in the text of the original document, and hence, the user is liable to overlook the fact that the comments have come to require updates. Further, in a case where the original document has been updated by a user different from the user in possession of the comments, this user might know nothing of the fact that the comments have come to require the updates.